1. Field of the Invention
The present invention relates to telecommunication networks, and more specifically to a method and apparatus for providing a permanent virtual circuit (PVC) between end systems in an asynchronous transfer mode (ATM network).
2. Related Art
Virtual circuits are often provisioned between end systems. End systems refer to devices such as customer premise equipment (CPEs), edge routers and switches at which virtual circuits terminate. The end systems interface with user systems (e.g., personal computer systems) and enable communication (and thus applications) between the user systems as is well known in the relevant arts.
Virtual circuits may be provided in various forms. For example, a switched virtual circuit (SVC) may be provisioned between two end systems. In general, an SVC is set up when required and released after use. Due to such set up and release operations on an as required basis, the resources (e.g., available bandwidth, memory) available in a telecommunications network may be utilized optimally. However, one problem with SVCs is that the overhead associated with the signaling protocols in provisioning and releasing the SVCs may be unacceptably high.
Accordingly, a permanent virtual circuit (PVC) may be provisioned between two end systems. A PVC is generally provisioned once, and continues existence even when not in use. Accordingly, the signaling overhead on a network in terms of set up and release is avoided.
One problem with PVCs is that the services (e.g., bandwidth, latency) provided by each PVC is generally fixed. However, the user applications may require different services at different times. One solution to such a problem is to over-design PVCs such that each PVC is configured to provide the most demanding (e.g., highest required bandwidth, lowest required latency) services.
Such a solution may require each PVC be allocated the maximum necessary resources corresponding to the demanding of services. However, when the user applications do not require all of the allocated resources, the available resources may go under-utilized. The under-utilized resources may not be available for use by other virtual circuits, which may lead to sub-optimal performance and/or the solution not scaling to serve more virtual circuits. The solution may accordingly not be acceptable at least in some environments.
In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. The drawing in which an element first appears is indicated by the leftmost digit(s) in the corresponding reference number.